Method and apparatus for translating digital data into an analog signal
US5774084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Apr 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/825
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A pulse width modulation (PWM) circuit translates digital data into an analog signal. The PWM circuit includes at least a digital counter, a significance reverser, and a comparator circuit. The significance reverser reverses the relative order of significance of at least two bits in the count words generated by the counter. The comparator determines whether the magnitude of a digital input word is greater than the magnitude of the reversed order count word. The PWM circuit produces a high output when the magnitude of the input word is greater than the magnitude of the reversed order count word and a low output when the magnitude of the input word is not greater than the magnitude of the reversed order count word. The analog output produced by the PWM circuit includes a number of pulses evenly distributed during the count cycle of the counter, and the input word indicates a duty cycle for the analog output. The PWM circuit includes a programmable output gain feature and an output interface that mimics the output configuration of conventional phase/frequency detector circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.